The invention relates to a device for supplying electronic components to a pick-up position, for example for the purpose of an automatic picking-up of the components by a placement machine and placing them on a printed circuit board, wherein at least two supply carriers are movable towards said pick-up position, said supply carriers being each provided with recessed portions each accommodating an electronic component, which recessed portions are shielded off by means of a covering which is removable during operation.
Such devices are also called xe2x80x9ctape feedersxe2x80x9d and are used for supplying large numbers of, usually small electronic components to a placement machine, which picks up the components and then places them on a printed circuit board. The electronic components are for this purpose packed in a supply carrier or tape which is unwound from a reel, and the components can be picked up by the placement machine after a covering foil has been removed.
Tape feeders with several tape transports (two in this case) in one housing are known from, for example, European patent no. 0 496 586. In this publication, two supply reels are accommodated in the housing, each with a wound supply carrier with packed electronic components. During operation, the two supply carriers are conducted next to one another to a pick-up position where the two types of electronic components can be taken up by one placement machine after the two covering foils have been removed.
This renders it possible to process two or more types of electronic components supplied next to one another by means of one placement machine.
In another known embodiment, the two (or more) supply carriers are located one behind the other. This has the disadvantage that the placement machine has to perform considerable, time-consuming displacements between the various pick-up positions.
In the embodiment of EP-B-0 496 586, the gain in constructional space is limited: the total width of the device is at least equal to the total widths of the supply carriers situated next to one another. If several tape transports are placed next to one another, the placement machine still has to perform time-consuming displacements in lateral direction, whereby the quantity of picked-up and placed electronic components per unit time is limited.
The invention has for its object to counteract the above disadvantage and to provide a tape feeder with several tape transports in which the placement machine can process more than one electronic component type while the width of the device remains unchanged.
According to the invention, the device is characterized in that the supply carriers partly overlap in lateral direction adjacent the pick-up position, but such that at least the recessed portions of an overlapped supply carrier are freely accessible to the component placement machine in the pick-up position.
This stepped or staggered mounting of the various supply carriers in the housing renders it possible to achieve a further gain in constructional space. The total width of the device is smaller now than the sum of the widths of the supplied carriers. Since the pick-up positions of the supply carriers are closer together, the placement machine can handle the same number of electronic components with smaller displacements between the pick-up positions.
Alternatively, a placement machine can serve more pick-up positions across the same original width thanks to the saving in space, which increases the speed and efficiency of the tape feeder and the placement machine.